Transformation of Trichoderma viride using the Neurospora crassa pyr4 gene and its use in the expression of a Taka-amylase A gene from Aspergillus oryzae

Abstract

A pyrG mutant of Trichoderma viride, a very efficient cellulase producer, was isolated from among 5-fluoroorotic acid-resistant mutants. The mutation was complemented with the pyr4 gene of Neurospora crassa and used as a selection marker for the transformation of T. viride. A plasmid vector, pDJB1-Taa, carrying both the pyr4 gene and a gene encoding Taka-amylase A from Aspergillus oryzae, was constructed and introduced into protoplasts of T. viride pyrG-. The transformation frequency was 1-10 transformants (3 on average) per μg DNA. One transformant showed highly elevated α-amylase production (about 17 times higher than the recipient level) and the integration of more than one copy of the Taka-amylase gene. © 1990 Springer-Verlag.